Another suggestion to consider. Try not to use "but" because it is a flag that you are about to discount what you just said. Here's an alternative to the above, where you simply replace "but" with "and". (Also note saying why you like something really helps too.)

"Yes, I like that because it would help with X, and have you have you considered the cost?"

Usually "but" can be replaced with "and" fairly smoothly. However, if not, you can do something like:

"Yes, I like that because it would help with X. I wonder how much it would cost, both for the licenses and for the effort?"